In the prior art there are known decorative pieces that are to be added to a portable object such as a watch and that consist of an aesthetic element inlaid on the elements of said portable object. For example, there exist watch bezels decorated with patterns such as signs. These bezels, which can be made of ceramic, can be marked in various ways and with various materials, such as gold, silver or platinum. The marking may be embossed or at a depth. In the case of deep marking, this is achieved by filling preformed hollows in the support. The principle used for performing such marking consists in depositing a layer of conductive primer by physical vapour deposition (PVD). Once the primer layer has been deposited, the hollows are filled with metal by electroforming. This method consists in dipping the piece to be marked in a bath containing metallic ions and passing an electric current through the bath in order to deposit metal atoms from the bath onto the piece to be decorated. The hollows are then filled with metal, thus allowing said marking to be achieved.
However, this type of method is complex and extremely slow. Indeed, the method requires a heavy material and includes numerous steps requiring extremely precise parameter control for the marking to be successful.
Moreover, the reproducibility of this electroforming method is dependent upon the constancy of external parameters such as pressure, temperature, time and the concentration of chemical elements, which involves significant monitoring of the method. Thus deviations from the method and thus the heterogeneity of the manufactured pieces can thus easily occur. It should also be mentioned that this electroforming method can only inlay chemical elements that are compatible with electroforming.
Finally, this electroforming method cannot deposit chemical elements beyond a certain thickness, which limits the depth of the hollows. Consequently, a maximum deposition thickness of 400 μm is generally the limit observed.
Decorative pieces formed of a metal support in which elements such as glass are inlaid are also known from the prior art. For this, the elements to be inlaid are arranged in a mould, then the metal used as support is poured over the elements. Everything is then cooled, and then polished, to form the final piece.
However, one drawback of this method is that shrinkage phenomenon is inevitable when the liquid alloy solidifies in crystalline form. This phenomenon then either causes the inlaid elements to come loose, or significant mechanical stress on the inlaid elements that may cause them to break. This method can only inlay elements whose melting point is higher than that of metal. In the particular case of the ceramic-metal system, an additional limit of this method is the long process time. Indeed, the poor resistance of ceramic to thermal shocks involves slow heating and cooling speeds.